Whole genome sequencing and comparative genomic analyses of Planococcus alpniumensis MSAK28401T, a new species isolated from Antarctic krill

Background Extremophiles have attracted much attention in the last few decades, as they possess different properties by producing certain useful metabolites. However, the secondary metabolism of the extremophiles of Antarctic krill has received little attention. Results In this study, a new bacterial strain MSAK28401T from Antarctic krill was isolated and identified. The results of analysis on phenotypic, chemotaxonomic, and genomic characteristics showed that the strain MSAK28401T belongs to the genus Planococcus. Cells of this strain were coccoid (0.89–1.05 μm) and aerobic. The majority of the fatty acid content was C15:0 anteiso (37.67 ± 0.90%) followed by C16:1 ω7c alcohol (10.37 ± 1.22%) and C16:0 iso (9.36 ± 0.71%). The calculated average nucleotide identity and DNA–DNA hybridization values between the strain MSAK28401T and type strains P. citreus DSM 20549T and P. rifietoensis M8T were lower than 91 and 70%, respectively. The strain MSAK28401T (=KCTC 43283T and MCCC 1k05448T) represented a new member of the genus Planococcus and was named P. alpniumensis sp. nov. Moreover, genes involved in the degradation of aromatic compounds (e.g., salicylate, gentisate, and quinate) were found in the genome, implying that strain MSAK28401T has an aromatic compound as its potential metabolite. This work will help us understand the genomic characteristics and potential metabolic pathway of Planococcus from Antarctic krill. Conclusions This study reported the genomic information and phenotypic characteristics of the new strain P. alpniumensis MSAK28401T isolated from Antarctic krill, and provided the genome information of Planococcus strains for further studying the function roles in aromatic compound metabolism.

Effect of Oxidation on the Formation of Disinfectant By-products of Low Molecular Weight Organic Matter

Some natural organic compounds (NOC) such as aromatic compounds can trigger the formation of disinfection by-products (DBPs). In chlorination (disinfectant) process resultant water quality depletes. Some safe alternative oxidants are needed for cleaning water pollutants. KMnO4 had shown better oxidation results, especially for reducing aromatic and non-aromatic organic compounds present in water. The aim of this study was to analyze the effect of KMnO4 and Ca(OCl)2 oxidants on the concentration of high and low molecular weight organic matter including aromatic compounds in the water sample. In this experiment, artificial organic compounds, namely sinapic acid (high molecular weight aromatic compound) and resorcinol (low molecular weight aromatic compound) were used to identify the characteristic of organic matter under different molecular weights. Sinapic acid and resorcinol were oxidized by using KMnO4 and Ca(OCl)2 with a minimum contact time of 60 minutes. Samples were analyzed for aromatic contents and total organic carbon (TOC) before and after completion of the experiment by using UV-Vis spectrophotometer at 254 nm wavelength (UV254). It has been observed that both oxidants increased TOC concentration. Ca(OCl)2 produces a higher percentage of organic matter degradation by-products (DBPs) such as chloroform (CHCl3) a highly toxic compound than KMnO4. Since Ca(OCl)2 has a higher oxidation potential than KMnO4. It has been observed that KMnO4 is a safer oxidant than Ca(OCl)2 as potassium permanganate produces less amount of DBPs.

Genomic Aromatic Compound Degradation Potential of Novel Paraburkholderia Species: Paraburkholderia domus sp. nov., Paraburkholderia haematera sp. nov. and Paraburkholderia nemoris sp. nov.

We performed a taxonomic and comparative genomics analysis of 67 novel Paraburkholderia isolates from forest soil. Phylogenetic analysis of the recA gene revealed that these isolates formed a coherent lineage within the genus Paraburkholderia that also included Paraburkholderiaaspalathi, Paraburkholderiamadseniana, Paraburkholderiasediminicola, Paraburkholderiacaffeinilytica, Paraburkholderiasolitsugae and Paraburkholderiaelongata and four unidentified soil isolates from earlier studies. A phylogenomic analysis, along with orthoANIu and digital DNA–DNA hybridization calculations revealed that they represented four different species including three novel species and P. aspalathi. Functional genome annotation of the strains revealed several pathways for aromatic compound degradation and the presence of mono- and dioxygenases involved in the degradation of the lignin-derived compounds ferulic acid and p-coumaric acid. This co-occurrence of multiple Paraburkholderia strains and species with the capacity to degrade aromatic compounds in pristine forest soil is likely caused by the abundant presence of aromatic compounds in decomposing plant litter and may highlight a diversity in micro-habitats or be indicative of synergistic relationships. We propose to classify the isolates representing novel species as Paraburkholderia domus with LMG 31832T (=CECT 30334) as the type strain, Paraburkholderia nemoris with LMG 31836T (=CECT 30335) as the type strain and Paraburkholderia haematera with LMG 31837T (=CECT 30336) as the type strain and provide an emended description of Paraburkholderia sediminicola Lim et al. 2008.